Showing papers in "Journal of Dairy Science in 1961"

TL;DR: An improved rumen fluid agar medium was developed that permitted the growth of about double the numbers of bacteria from ruminal contents grown in the medium previously used, and allowed much larger numbers of colonies to be counted and isolated with greater ease from a given volume of medium and after longer incubation periods.

TL;DR: Information on the survival, growth, enumeration, and biochemical activities of psychrophiles was documented and interpreted with the purpose of summarizing the available information and encouraging further investigation of this important group of microorganisms.

TL;DR: The highly significant correlation between EGR and total sperm removed in a depletion should permit estimation of EGR in living animals by depletion trials of about 20 ejaculates, and gonadal sperm reserves were not significantly correlated to epididymal sperm reserves in SR bulls.

TL;DR: Diet apparently exerted no major effect on levels of any of the digestive enzymes in calves divided into comparable groups at birth.

TL;DR: In this article, the authors used dairy heifers to study factors that influence the rate of consumption of alfalfa silage and concluded that the dry matter content of he forage when ensiled, and the resulting fermentation process, are very important factors in determining the consumption of the resulting silage.

TL;DR: The preservation efficiency and chemical quality of silages made from direct-cut and heavily wilted (haylage) alfalfa were compared in three successive years and haylage surpassed high-moisture direct- cut silage in these respects with the exception of milk production, which was about equal on the two types of silage.

TL;DR: In this paper, a procedure was developed for quantitative analysis of the fatty acids of milk fat, where methyl esters of the acids were prepared by methanolysis, extracted with ethyl chloride, and separated by gas-liquid chromatography (GLC), with diethylene glycol succinate as liquid phase.

TL;DR: In this article, the effects of heat at 85 or 90°C on skimmilk and artificial systems composed of caseinate centrifuged from skim milk and dispersed in milk dialysate with and without added milk serum proteins were investigated.

TL;DR: The experimental evidence presented in this paper substantiates the theory that the lignin in forages acts as a physical barrier between the cellulose and cellulolytic rumen bacteria.

TL;DR: In this article, sodium or potassium bicarbonates (1 lb/day) were added to the rations of cows fed grain to appetite and 2 lb of long or pelleted hay.

TL;DR: A technique for determining the gonadal and extra-gonadal sperm reserves of bulls by direct counting is described and replicate counts should be made on separate subsamples of the entire suspension.

TL;DR: In this paper, the pH-heat stability of milk was investigated and it was concluded that the denatured β-lactoglobulin-casein (or Kcasein) complex is the pH sensitive component.

TL;DR: In this paper, the authors analyzed milk samples from each of two cows at intervals throughout a lactation period and analyzed for heat stability (over a range of pH), various inorganic constituents, and seven protein constituents (by electrophoresis).

TL;DR: Lactulose is produced from lactose during the heat processing and storage of certain dairy products and seems to have unique growth-promoting properties for certain desirable types of Lactobacilli in the intestinal tract of the infant.

TL;DR: The uterus of the repeat-breeder during the luteal phase of the estrual cycle appears to be more resistant to bacterial invasion than that of the first-service animal, possibly indicating a deficiency of progesterone action.

TL;DR: In this paper, the authors measured blood reducing sugar responses in dairy animals of five age groups (mean ages: 22, 50, 136, 227, and 600 days) following ingestion of single test meals of each of the following in water: glucose, maltose, lactose, sugar, sucrose, amylose, Amylopectin, Flojel, and tapioca starch.

TL;DR: The results indicate that temporary environmental conditions are more important during first and last stages of production than during the middle stages, when genetic and permanent environmental differences between cows provide relatively more control over production.

TL;DR: Seasonal variation in breeding efficiency was studied, using breeding records of dairy cows inseminated in Arizona with semen collected in three different climatic areas to point to the female as the major contributor to the summer depression.

TL;DR: Weigh and fatty acid composition of the lipid fractions have been determined from bovine serum lipoproteins separated ultracentrifugally at a solvent density of 1.063g/ml as mentioned in this paper.

TL;DR: The data suggest that a threshold level of progesterone production represented by a luteal progester one level of the order of 100 μ g.

TL;DR: Data compiled on intramammary infusions, intramuscular injections, and oral administration of antibiotics and their vehicles illustrate that wide variations exist concerning the relative persistence of the amount of antibiotics found in milk.

TL;DR: In this paper, the authors studied the hydrolysis of milk fat in the abomasum of a young calf, and the results showed that the fat contained in the young calf can be divided into three fractions: butyric, valeric and higher fatty acids.

TL;DR: Significant differences between interaction effects indicated the desirability of constructing ratio factors while simultaneously considering age at calving, season of calve, month of lactation, and whether the record is milk or fat.

TL;DR: Electroejaculated semen is at least comparable in quality to semen collected in the artificial vagina and it is adaptable to nearly all bulls, with no selection on ability or desire to serve the AV.

TL;DR: In this article, the expectation of the sums of squares and cross products of deviations from four contemporary averages in one-way classification analyses were determined in terms of a more complex model.

TL;DR: In this article, a tentative energy standard is presented, in which the TDN allowances are graduated in terms of milk output per day, where each allowance is assigned to each cow according to the consumption of a specific amount of forage per day.

TL;DR: Progesterone and 20 β-ol per gram of luteal tissue were not highly correlated at any stage of pregnancy and the correlation for the study was only 0.21.

TL;DR: Monthly milk fat yields have been analyzed to obtain estimates of heritability, repeatability, genetic and phenotypic correlations, indicating that in addition to environment playing an increasingly more important role in determining production as lactation progresses, the sets of genes determining total yield and end-of-lactation yield are not altogether the same.